title: Serum S100B levels correlate with clinical benefit in a metastatic melanoma patient treated by CTLA-4 blockade: a case report.
abstract: BACKGROUND
  Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an immunoregulatory molecule expressed by activated T cells. In patients with metastatic melanoma, anti-CTLA-4 antibody therapy with ipilimumab achieves durable cancer regression in approximately 10-15% of patients. In the face of complex and sometimes delayed tumor response patterns, prognostic and predictive biomarkers are needed to monitor therapy outcomes and to identify early potential long-term survivors who might also benefit from therapy re-induction.
  
  
  METHODS
  The clinical case of a 49-year-old male patient with metastatic melanoma and unfavorable prognostic factors is presented. The time course of the serum biomarker S100B during initial anti-CTLA-4 therapy correlated very well with the clinical situation and, in the present case, proved its potential value as an early biomarker of a subsequently observed radiological response in this stage IV melanoma patient. The observed clinical response lasted for more than 24 months.
  
  
  CONCLUSIONS
  Further efforts are required to better understand the patterns of response and the immunological tumor response in patients undergoing CTLA-4 blockade. A validation of S100B as a marker to identify early long-term responders among patients treated with ipilimumab is warranted.
authors.affiliation: Department of Dermatology, University of Mainz, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Loquai
authors.forename: Tina
authors.initials: T
authors.lastname: Müller-Brenne
authors.forename: Simin
authors.initials: S
authors.lastname: Schadmand-Fischer
authors.forename: Stephan
authors.initials: S
authors.lastname: Grabbe
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood*; D060908:CTLA-4 Antigen / Q000037:antagonists & inhibitors*; D006801:Humans; D000074324:Ipilimumab; D008297:Male; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism / Q000556:secondary; D008875:Middle Aged; D015203:Reproducibility of Results; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D060908:CTLA-4 Antigen; D000074324:Ipilimumab; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human